Chemistry Reference
In-Depth Information
100
90
80
70
60
50
40
30
20
10
0
PC
PI
PE
PA
Fig. 15.10
Rate of hydration of different phosphatides PC, phosphatidyl choline; PI, phosphatidyl inosi-
tol; PE, phosphatidyl ethanolamine; PA, phosphatidic acid; HPLC, high performance liquid chromatography.
lead to elevated PA levels. Analysis of five rapeseed oil samples containing on average
450 ppm of phosphorus gave the distribution of the four phospholipid types, shown in
Fig. 15.11. Water degumming of this oil could not bring the phosphorus content to
10 ppm
due to the relatively high content of non-hydratable phosphatides and enzymatic degumming
is required.
21
The process of degumming oils with Lecitase Ultra consists of three steps:
<
1.
Bringing the lecithin to an oil/water interface to allow the enzyme to react
a.
Mixing with citric acid to chelate the metal ions (Ca
++
,Fe
++
, etc.) which normally
hold the lecithin within aggregates in the crude oil.
b.
Applying high shear mixing to provide a large surface area for the lecithin through
emulsification.
2.
Reacting the lecithin with enzyme
a.
The phospholipase converts the aggregated lecithin to lyso-lecithin.
3.
Separation
a.
Centrifugation in one step, which efficiently removes the water phase, which contains
all the lecithin. The phosphorus content in the oil should be
<
10 ppm after
centrifugation.
0.6
0.5
0.4
0.3
0.2
0.1
0
PE
PI
PC
PA
Fig. 15.11
Phosphatide content of rapeseed oil determined by HPLC analysis.
